A passive optical network (PON) is one system for providing network access over “the last mile.” The PON is a point to multi-point network comprised of an optical line terminal (OLT) at the central office, an optical distribution network (ODN), and a plurality of optical network terminals (ONTs) at the customer premises. The ODN comprises optical fibers, couplers, splitters, distributors, filters, and other passive optical devices, which connect the OLT to the ONTs. The quantity of ONTs and the specific configuration of passive optical components determine the PON's topology.
Various optical properties can be measured at the OLT and the ONTs to monitor optical layer operations in the PON. These optical properties comprise insertion losses and transmission delays between the OLT and the ONTs. The optical properties quantify the problems in the PON, but do not provide any specific information regarding problems with specific PON components. For PON topologies where relatively few ONTs are connected to the OLT with one or few passive optical components, problems within the PON components are relatively easy to identify. However, for PON topologies where many ONTs are connected to the OLT with a complex branching ODN, identifying problems with individual components becomes exceedingly difficult, if not impossible.